Electromagnetic operator



Aug. 9, 1966 J. s. LoRY ETAL ELECTROMAGNETIC OPERATOR 'Filed Sept. 24, 1963 JOHN S. I ORY HARRY ASHVVORTH HYIVIAN l.. GLUCK @za/ ATTORNEYS 3,265,941 ELECTRMAGNETIC DPERATR liohn S. Lory, Bloomfield, Harry Ashworth, Thompsonville, and Hyman L. Gluck, West Hartford, Conn., as-

The presen-t invention relates to improvements in electromagnetic operators which are particularly adaptable for actuating electrical switches.

It is a principal aim of the present invention to provide a new and improved electromagnetic operator for use in high gravity environments, as in aerospace vehicles for operating electrical switches of the type shown in the pending application entitled Switch of lohn S. Lory et al., Serial No. 270,447.

It is another .aim of the .present invention to provide a new and improved electromagnetic operator havin-g a compact and economical construction and which provides reliable operation with a minimum of electrical energy.

It is a further aim of the present invention to provide an 'improved electromagnetic operator which gives quick and effective operation even when the opposing load is greater than its incipient magnetic attractive force.

Other objects will be in part obvious and in part pointed out more in detail hereinafter.

The invention accordingly consists in the features of construction, combination of elements and arrangement of parts which will be exemplified in the construction hereafter set forth, and the scope of the application of which will be indicated in the .appende-dclaims.

In the drawings: l

FIG. 1 is a generally longitudinal section view, partly broken away, of a switch embodying the electromagnetic operator of the present invention;

FIG. 2 is a transverse section view of the switch taken along line 2 2 of FIG. l; and

FIG. 3 is an enlargement of a portion of FIG. 1.

Referring now to the drawings in detail, a preferred embodiment of the electromagnetic operator of the present invention is shown installed for operati-ng a switch of the type described in the aforementioned pending application of John S. Lory et al., lthe switch being one having particular application in aerospace vehicles designed to operate under considerable gravity forces.

The switch has an elongated casing or support body with a longitudinally extending opening or cavity 12 adjacent one end thereof, and a pair of longitudinally extending coaxial bores of varying diameters generally designated by the numerals 14 and 16. The cavity 12 and the bores 14, 16 thereby provide a longitudinal passage in the casing 10, which passage is dimensioned to receive the parts of the switch. As seen in FIG. 2, the cavity 12 is of generally rectangular cross section and opens into a recess 17 in the casing defined in -part by a peripheral lip 18 about the cavity 12. A molded insert 20 is received within the Vcasing cavity and is accurately positioned therein by the engaging peripheral shoulders 23 and 24 provided by an outer flange 26 of the insert and a complementary recess 28 in the casing. The insert is securely retained in the casing by crimping the lip 18 over a peripheral chamfered edge 30 of theinsert.

The insert 20 has a central longitudinal bore 32 coaxial with the casing bores 14 and 16 and has a plurality of States Patent A movable contact support or spool 40 is loosely mounted in the insert bore 32 for longitudinal movement, to the lef-t as seen in the drawing, from a preset position with its inner end 42 in engagement with the casing shoulder 44. The spool is actuated to its alterna-tive released position where the Iopposite end 46 of the spool engages the opposed shoulder 48 of the casing by a compression spring 45 interposed between the spool and a lateral shoulder of the casing 1t). The spool has ve llongitudinally spaced lands defining four annular recesses which receive a corresponding number of annular resilient contacts 50, only one of which bein-g shown in the drawings for simplicity. The annular recesses and therefore the resilient contacts 50 in this embodiment are positioned out of electrical contact with the stationary contacts 22 when the spool 40 is in the preset position. When the spoolis in its alternative released position the resilient contacts 5t) are in engagement with the stationary contacts to complete the electrical circuit between the pairs of terminals 38.

The spool 40 is connected for longitudinal movement with a plunger 64 slideably mounted in a bore portion 66 of the longitudinal bore 14. The plunger 64 has an enlarged circular head 68 received within a T-shaped slot in the spool 4i) which thereby enables the plunger to be assembled with the spool when the insert and spool subassembly is placed in the cavity 12 of the casing.

The spool is retained in its preset position shown in the drawings by a one-way latch, generally denoted by the numeral 72, which is adapted to retain the plunger 64 and the spool-40 against the force of the compression coil spring 45. This retention is provided by the engagement of a plurality of ball bearings 74 of the latch 72 with a reduced rod 76 of plunger 64. Preferably, there are three ba-ll bearings 74 equally spaced in a transverse plane angularly abo-ut the rod 76. The ball bearings are assemble-d in three radially extending apertures A77 in a carrier sleeve '78 that is slideably mounted on the rod 76 intermediate the rod and a'camming bushing 80. The radial apertures 77 are preferably inwardly tapered at 81 to provide pockets which receive the balls 74 and thereby assist in retaining the ball bearings with the carrier sleeve during assembly ofthe switch. The camming bushing 8d has a frustcconical or `axially tapering rearwardly facing camming surface S6 engageable by the ball bearings which thereby serve as cam followers. A compression coil spring encircling the carrier sleeve 78 is cornpressed between a radial shoulder 92 of the car-Iier sleeve andan opposed radial flange 93 of an end bushing 94, thereby `biasing the ball bearings into engagement with the frustoconical camming surface S6 to provide t-he oneway laltchi-ng of the plunger 64. The camming bushing 80, the end bushing 94, and a washer cap 95, all of the same outside diameter, are secured within a complementary bore portion 98 of the bore 14 thereby locating the camming surface 86 and the carrier sleeve '78 in coaxial relationship with the plunger 64. The washer capv provides a support for the rod 76 which cooperates with the flange 93 for enclosing and thereby sealing the latching mechanism against foreign elements.

In .accordance with the present invention, an electromagnetic operator, generally denoted by the numeral 96, is received within the bore portion 93 of the bore 14 rearwardly ofthe latch. The electromagnetic operator includes, coaxially arranged with the casing 10, a central magnetic core 100, a Vpair `of insulating .sleeves 102, 106, an energizing coil 164, a magnetic sleeve 108 and a magnetic end piece 167 secured to the core 160. The electromagnetic opera-tor is rigidly retained within the casing 10 through the engagement of the magnetic sleeve 108 with thel bushing 94 and Vby crimping a peripheral lip 111 formed on the end of the casing over a beveled peripheral edge of a switch cap 1'12. The cap 112 engages an insulator bushing 114 bearing against the sleeve 108 and cap 107 and forms with the bushing 1-14 an enclosed cavity 116 which receives coil leads 118 electrically connected to terminals 120` integrally molded with the switch cap 112.

An armature of the electromagnetic operator, generally denoted by the numeral 130, .comprises a pair of outer a-nd inner cooperating armature elements 132, 134, respectively. The outer arama-ture element 132, of washerlike shape, encircles the inner armature element 134 and is adapted for longitudinal movement between active and inactive positivo-ns within an annulus dened by a shoulder 136 of the bushing 94 and an end shoulder 138 of the magnetic sleeve 108. The outer armature element 132 i-s biased away from the core 100 to its inactive position by a light compression spring 140 interposed between the element132 and a face portion 142 ofthe insulating sleeve 102. A-n inner portion of the rear face 144 of the armature elernent 132 is recessed to provide an annulus for receiving an `annular flange 146 of the inner armature element 134.

The inner armature element 134 is press-tit on the sleeve 78 whereby with the electromagnetic operator deenergized and the armature element 132 in its deactive position the flange 146 is longitudinally spaced from an inner flange portion 148 of the armature element 132. Preferably, this longitudinal spacing provides for slight axial overlappin-g of the armature elements 132, 134 to reduce the incipient air gap reluctance when the electromagnetic operator is energized. For the same reason, it is prefera-ble that the inwardly extending ange 148 of the armature element 132 is in close proximity with a cylindrical surface 152 of the armature element 134. e The core 100 is provided with an enlarged circular head 156 with a forward face 158 in the plane of t-he edge 138 of the magnetic sleeve 8. The core head 156 is of larger diameter th'an `the inner arma-ture element 134 whereby upon energization of the electromagnetic operator a'nd movement Iof the armature elements from their in-active to their active positions the core is engaged simu taneously by the armature elements 132, 134, for which purpose the annul'us provided on the armature element 132 is dimensioned so that when the armature elements are in contact, their rear faces lie in a common transverse plane. The magnetic circuit of the electromagnetic operator therefore comprises the core 100, cap 107, sleeve 108, and the armature elements 132, 134, whereby, upon energizing the coil 104, the armature elements .are attracted rearwardly to reduce the air gap reluctance in the magnetic circuit.

In order to ensure reliable operation of the latching mechanism, even in environments where the gravitational force on the switch urges the sleeve 78 in a longitudinal direction tending to release the latch, to the right as seen in the drawings, the compression spring 90 must be sufficiently stiff to oliset any gravitational force on the carrier sleeve 78. Accordingly, the summation of the incipient magnetic forces on the armature elements 132, 134 may be insuicient to overcome the bias of the spring 90 unless the electromagnet is made undesirably large. I n accordance with the present invention, however, the electromagnetic operator is capable of releasing the latch even though these incipient forces are less than the opposing summation of force and the spring 90 and the static friction between the Iball bearings 'and the rod 76 and Ibushing 80. The outer armature element y132 moves initially from its inactive position independently to the armature element 1-314 against the hias of the light 4coil spring #140 into contact `with the armature element 134. Whereupon the ange 148 of the armature element 132 engages the overlapping lange 146 of the armature element 1'34 which thereby receives the impact of the armature element 132 to assist in shifting the sleeve 78 for releasing the latch. The mass and independent motion of the armature element 132 are therefore made to develop a suilicient inertial force for overcoming the bias of the spring and the static resistance between the ball bearings 74 and the bushing 80 and rod 76. The armature elements 132, 134 will thereafter normally be drawn into contact with the core and the sleeve 108 due to the increased attraction resulting from the substantially reduced air gap reluctance in the magnetic circuit.

In operation the spool 40 can be preset, as by a tool inserted within the bore 16, with the one-way latch 72 automatically retaining the spool in the preset position for subsequent selective activation by the electromagnetic operator 96. In the preset condition the switch is capable of withstanding loads of over 500 gs even in the longitudinal directions, without causing an inadvertent release of the latch. However, upon energizing the electromagnetic operator 96, the latch is released to enable the spring `45 to shift the spool for completing the electrical circuits between the pairs of terminals 38. This latch releasement is ensured by the inertial force of the armature element 132 against the" armature element 134. Thus, it can be readily seen that the improved electro-V magnetic operator of the present invention provides a highly compact and economical construction which is operable with minimum electrical power. Additionally, the improved electromagnetic operator is useful even where the opposing force is greater than its incipient magnetic attraction for providing responsive and quick actuation.

As will be apparent to persons skilled in the art, various modications and adaptations ofthe structure above described will become readily .apparent without departure from the spirit and scope of the invention, the scope of which is defined in the appended claims.

We claim:

1. In an electrical switching mechanism having an electrical switch; a shiftable switch controller; a latch for retaining the switch controller in one operative position, said latch having a longitudinally reciprocable control member operable in one longitudinal direction for releasing the latch and a spring urging the control member in the opposite longitudinal direction; and an electromagnetic operator having an electromagnet and an armature longitudinally shiftable by the electromagnet in said one direction from an inactive position for actuating the control member in said `one direction; the improvement wherein the electromagnetic operator comprises, an armature having an inner circular armature element connected to the control member and an outer annular armature element, one of said armature elements having an annular flange adapted for engagement with the `other armature elem-ent, said flange being longitudinally spaced from the other armature element lwith the outer armature element in its inactive position; a magnetic core longitudinally spaced from the control member, an electric coil encircling the core, and a magnetic sleeve encircling the coil whereby upon energization of the electrical coil the outer armature element initially shifts independently of the inner armature element to develop momentum which assists upon engagement with the inner armature element in actuating the control member in said one direction.

2. In -alcontrol device having a longitudinally reciprocable control member and an electromagnetic operator having an electromagnet and an armature longitudinally shiftable by the electromagnet from an inactive position longitudinally spaced from the electromagnet toward the electromagnet to an active position to decrease the rel-uctance between the electromagnet and the armature, the armature thereby longitudinally actuating the control member from a first position, the improvement wherein the armature comprises a longitudinally shiftable rst impact armature element and a second impact receiver armat-ure element connected to the control member, said first and longitudinal movement of the first armature element relative to the second armature in the longitudinal direction toward the electromagnet @before engagement therewith,

said first armature element being longitudinally shiftable `from its inactive position toward the electromagnet the electromagnetic force thereof into engagement with the secondarmature element to reduce the reluctance between the first armature element andthe electromagnet and `to develop momentum for actuation of the second armature, whereby upon energization of the electromagnetic operator the first armature element is initially shifted independently of the second armature element longitudinally toward the electromagnet to develop momentum which assist upon impact with the second armature element in actuating the control member and which at the same time reduces the reluctance between the armature and ythe electromagnet before impact to increase the magnetic force on tbe armature. K

3. The improvement of claim 2 wherein the electromagnetic operator further comprises -a magnetic core longitudinally spaced from the control member and a magnetic sleeve encircling the core and wherein said armature elements together provide a magnetic circuit between the core and sleeve. y

4. The improvement 1of claim 2 wherein the first and second armature elements are coaxially mounted and are provided with opposed cooperating cylindrical -surfaces in contiguous relationship to reduce the reluctance between the elements.

S. In a control device having Ia longitudinally reciprocable control member and an electromagnetic operator having an electromagnet and an armature longitudinally shiftable by the electromagnet from an inactive position for actuating the control member from a first position; the improvement wherein the electromagnetic operator comprises an armature having a first impact armature element and a second impact receiving armature element connected to the control membensaid first and second armature elements having engageafble parts longitudinally spaced with the armature and control member in their inactive and first positions respectively, said first armature element being longitudinally shiftable by the electromagnet from its inactive positionkinto engagement with the second armature element whereby upon energization yof the electromagnetic operator the rst armature element is initially shifted lindependently of the second armature element to develop momentum which assists upon impact with the second armature element in actuating the control member from its first position; and wherein the electromagnetic operator further comprises a magnetic core longitudinally spaced from the control member and a magnetic -sleeve encircling the core; said armature elements together providing a magnetic circuit between the core and sleeve; said armature elements being coaxially arranged with their engageable parts being provided iby an annular flange on one of the element adapted for engagement with the other of the elemen-ts, and said core having a face engageable by both of the armature elements.

6. In an electrical switching device having an electrical switch; a shiftable switch controller; a latch for retaining the switch controller in one operative position, said latch having a longitudinally reciprocable control member operable in one longitudinal direction for releasing the latch and a spring urging the control member in the opposite longitudinal direction; and an electromagnetic operator having an electromagnet and an armature longitudinally shiftable by the electromagnet in said one longitudinal direction from an inactive position longitudinally spaced from the electromagnet toward the electromagnet to an active position to decrease the reluctance between the electromagnet and the armature, the armature thereby longitudinally actuating the control member in said one longitudinal direction, the improvement wherein the armature comprises a longitudinally shiftable first impact armature element and a second impact receiver armature element connected to the control member, said first 'and second armature elements having engageable parts longitudinally spaced to allow longitudinal movement of the firs-t armat-ure element relative to the second armature in the longitudinal direction toward the electromagnetic before engagement with the second armature element, said first armature element being longitudinally shiftable from its inactive position toward the electromagnet by the electromagnetic force thereof into engagement with the second armature element to reduce the reluctance between the first armature element and the electromagnet and to develop momentum in the first armature element prior to its engagement with the second armature element, whereby upon energization of the electromagnetic operator the first armature element -is initially shifted independently of the second armature element longitudinally toward the electromagnet to develop momentum which assists upon impact with the second armature element in actuating the control member to release the -latch and which at the same time reduces the reluctance between the armature and the electromagnet before impact with the second armature element to increase the magnetic attraction of the electromagnet.

7. In an electrical switching device having an electrical switch; a shiftable switch controller; a latch for retaining the switch controller in one operative position, said latch having a longitudinally reciprocable control member operable in one longitudinal direction for releasing the latch and a spring urging the control member in the opposite longitudinal direction; and an electromagnetic operator having an electromagnet and an armature longitudinally shiftable by the electromagnet in said one direction from an inactive position for actuating the control member in said one direction; the improvement wherein the electromagnetic operator comprises an impact armature and an ini-pact receiver connected to the control memberI said impact armature and impact receiver having engageable parts longitudinally spaced with the armature in its inactive position, said impact armature being longitudinally shifted by lthe electromagnet from its inactive position into engagement with the impact receiver whereby upon energization of the electromagnetic `operator the impactl armature initially shifts independently of the impact receiver to develop momentum which assists upon impact with the receiver in actuating the control member in said one direction, and a spring biasing the impact armature in said opposite longitudinal direction to its inactive posiion.

References Cited by the Examiner UNITED STATES PATENTS 3,105,925 10/1963 Musgrave 3 l7-187 X BERNARD A. GILHEANY, Primary Examiner. JOHN F. BURNS, Examiner. G. HARRIS, JR., Assistant Examiner. 

1. IN AN ELECTRICAL SWITCHING MECHANISM HAVING AN ELECTRICAL SWITCH; A SHIFTABLE SWITCH CONTROLLER; A LATCH FOR RETAINING THE SWTICH CONTROLLER IN ONE OPERATIVE POSITION, SAID LATCH HAVING A LONGITUDINALLY RECIPROCABLE CONTROL MEMBER OPERABLE IN ONE LONGITUDINAL DIRECTION FOR RELEASING THE LATCH AND SPRING URGING THE CONTROL MEMBER IN THE OPPOSITE LONGITUDINAL DIRECTION; AND AN ELECTROMAGNETIC OPERATOR HAVING AN ELECTROMAGNET AND AN ARMATURE LONGITUDINALLY SHITABLE BY THE ELECTROMAGNET IN SAID ONE DIRECTION FROM AN INACTIVE POSITION FOR ACTUATING THE CONTROL MEMBER IN SAID ONE DIRECTION; THE IMPROVEMENT WHEREIN THE ELECTROMAGNETIC OPERATOR COMPRISES, AN ARMATURE HAVING AN INNER CIRCULAR ARMATURE ELEMENT CONNECTED TO THE CONTROL MEMBER AND AN OUTER ANNULAR ARMATURE ELEMENT, ONE OF SAID ARMATURE ELEMENTS HAVING AN ANNULAR FLANGE ADAPTED FOR ENGAGEMENT WITH THE OTHER ARMATURE ELEMENT, SAID FLANGE BEING LONGITUDINALLY SPACED FROM THE OTHER ARMATURE ELEMENT WITH THE OUTER ARMATURE ELEMENT IN ITS INACTIVE POSITION; A MAGNETIC CORE LONGITUDINALLY SPACED FROM THE CONTROL MEMBER, AN ELECTRIC COIL ENCIRCLING THE CORE, AND A MAGNETIC SLEEVE ENCIRCLING THE COIL WHEREBY UPON ENERGIZATION OF THE ELECTRICAL COIL THE OUTER ARMATURE ELEMENT INITIALLY SHIFTS INDEPENDTLY OF THE INNER ARMATURE ELEMENT TO DEVELOP MOMENTUM WHICH ASSISTS UPON ENGAGEMENT WITH THE INNER ARMATURE ELEMENT IS ACTUATING THE CONTROL MEMBER IN SAID ONE DIRECTION. 